Man has acclimated to his environment throughout the ages by adopting suitable shelter and clothing. In modern times, indoor environmental systems are of significant importance to those that live in harsh climates, particularly torrid or frigid climates. In addition, the type and amount of clothing worn is a critical requirement to those who venture outdoors. Sometimes, outdoor activities are planned during the more moderate temperature of the day, such as early morning or late evening. However, it often is required to be outdoors during the most inhospitable time of day which can lead to adverse medical reactions caused by prolonged exposure to harsh weather conditions. Consequently, taking the air-conditioned comfort or warmth typically associated with an indoor environmental system with us to the outside is a particularly appealing concept.
The prior art is replete with efforts to incorporate indoor environment systems within clothing articles. For example, U.S. Pat. No. 4,204,543 to Henderson, issued May 27, 1980, discloses a coolant band having a pocket in which a bag of freezable liquid or semi-liquid material may be inserted. The band may be worn on the head or about the body to provide a cooling effect. Similar bands are disclosed in U.S. Pat. No. 4,326,533 to Henderson, issued Apr. 27, 1982 and in U.S. Pat. No. 4,854,319 to Tobin, issued Aug. 8, 1989.
U.S. Pat. No. 4,484,363 to Varanese, issued Nov. 27, 1984, provides a cap which utilizes a removable cooling device in the forehead area of a cap. The cooling device is in the form of a sealed bag or container constructed from a water-impermeable material and containing a liquid or semi-liquid gel-like substance. U.S. Pat. No. 5,539,934 to Ponder, issued Jul. 30, 1996, discloses a protective helmet having a coolant bladder attached to the helmet and covering the entire cranium crown, the coolant bladder being filled with a ammonium-based fluid coolant. Similar devices for cooling headgear are disclosed in U.S. Pat. No. 4,138,743 to Elkins et al., issued Feb. 13, 1979 and U.S. Pat. No. 5,557,807 to Hujar et al., issued Sep. 24, 1996. All of the above-mentioned patents require that the bladder be filled with a fluid or gel based coolant, such as water or glycol, that is cooled in a refrigerator, freezer, or ice chest. A significant drawback to these cooling head gear is exposing the wearer to possible harm from the skin contact with a frozen substance. In addition, none of these patents enable the user to adjust the cooling level of the head gear. Moreover, the use of a chilled or frozen fluid-filled bladder creates unnecessary weight on the user's head which can create extreme discomfort to the wearer.
Several attempts have been made to design cooling headgear based upon evaporative principles. For example, U.S. Pat. No. 6,481,021 to Spell, issued Nov. 19, 2002, and U.S. Pat. No. 5,197,292 to McPherson, issued Mar. 30, 1993, provide articles of headgear, each having a small pouch attached to the rearward portion of a cap in which ice can be placed. As the ice melts, cool water runs down the neck and back of the wearer, providing him with cooling relief. One disadvantage to the type of headgear disclosed by Spell and McPherson is that water drips on the wearer, wetting clothing and making it impractical for many uses. Another disadvantage is that the user cannot adjust the cooling level; rather, the ice melts based upon ambient temperature.
In U.S. Pat. No. 5,940,880 to Phillips, an apparatus and method for providing coolant water to the head of a user during exercise is described, in which the user can control the amount of coolant (ice water) being delivered by means of a hand pump which conducts water from a bladder to an irrigation system disposed about the user's head. Like the Spell and McPherson patents, the Phillips device has limited use insofar as the user will get wet when the device is in operation. Moreover, the Phillips apparatus requires an air bladder and a water container which is carried on the user's back, as well as an elaborate irrigation system for wetting the user with cooled water. Finally, none of the cooling devices disclosed in the aforementioned patents can be easily incorporated into other articles of clothing.
Despite the attempts of the prior art, a need still exists for a cooling system for clothing articles that does not require placing the cooling source into a refrigerator, freezer, or ice chest. Such a system should utilize a gas or vapor based cooling agent, rather than a water or fluid based cooling agent which adds unnecessary weight and bulk. Such a system also should be lightweight and comfortable for long periods of wear. In addition, such a system should be rechargeable quickly and easily, such as from an aerosol can. Further, such a system should be designed in such a manner than it can be effectively used in all forms of clothing and apparel. Moreover, such a system should provide the wearer with the ability to instantly adjust the cooling level. Also, such a system should employ the use of water-proofing polymers and/or vapor impermeable polymers on the outside fabric in order to contain and improve the effectiveness of the cooling agent.